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arXiv · 1605.05727

Interstellar scintillations of PSR B1919+21: space-ground interferometry

V. I. Shishov·T. V. Smirnova·C. R. Gwinn·A. S. Andrianov·M. V. Popov·A. G. Rudnitskiy·V. A. Soglasnov
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Abstract

We carried out observations of pulsar PSR B1919+21 at 324 MHz to study the distribution of interstellar plasma in the direction of this pulsar. We used the RadioAstron (RA) space radiotelescope together with two ground telescopes: Westerbork (WB) and Green Bank (GB). The maximum baseline projection for the space-ground interferometer was about 60000 km. We show that interstellar scintillation of this pulsar consists of two components: diffractive scintillations from inhomogeneities in a layer of turbulent plasma at a distance $z_{1} = 440$ pc from the observer or homogeneously distributed scattering material to pulsar; and weak scintillations from a screen located near the observer at $z_{2} = 0.14 \pm 0.05$ pc. Furthermore, in the direction to the pulsar we detected a prism that deflects radiation, leading to a shift of observed source position. We show that the influence of the ionosphere can be ignored for the space-ground baseline. Analysis of the spatial coherence function for the space-ground baseline (RA-GB) yielded the scattering angle in the observer plane: $θ_{scat}$ = 0.7 mas. An analysis of the time-frequency correlation function for weak scintillations yielded the angle of refraction in the direction to the pulsar: $θ_{ref, 0}$ = 110 ms and the distance to the prism $z_{prism} \le 2$ pc.

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V. I. Shishov, T. V. Smirnova, C. R. Gwinn, A. S. Andrianov, M. V. Popov, A. G. Rudnitskiy, V. A. Soglasnov. 2017-03-07. Interstellar scintillations of PSR B1919+21: space-ground interferometry. https://doi.org/10.1093/mnras%2Fstx602

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